There has been known a tablet printing apparatus that uses an inkjet print head to print a character, a letter, a mark, or the like on a tablet. In the tablet printing apparatus, tablets are conveyed by a conveyor belt, and ink is ejected from the ejection port of the inkjet print head (nozzle opening) located above the conveyor belt toward each tablet passing under the print head to perform printing on the tablet.
Meanwhile, the tablets sucked and conveyed by the conveyor belt may sometimes shake on the conveyor belt. This is due to continuous vibration caused by the supply of the tablets dropped from above the conveyor belt or is due to a slight swing of the moving conveyor belt, or the like. If the tablet continues to shake until it passes under the print head, normal printing cannot be performed. Therefore, it is necessary to suppress the shaking motion of the tablet on the conveyor belt as much as possible.